Cummins B ISB QSB Oil Cooler | 3959031 | 7-Plate | 2003-2007 5.9L

New aftermarket Interstate-McBee oil cooler for Cummins ISB and QSB 5.9L engines, part number 3959031. This is the 7-plate stacked-plate cooler that regulates engine oil temperature. Direct-fit replacement for the factory cooler. Gaskets are not included.

Key Features:

• New aftermarket 7-plate oil cooler for the Cummins ISB / QSB 5.9L
• Regulates engine oil temperature to protect bearings, camshaft, and turbocharger from heat-related wear
• Direct replacement for Cummins 3959031
• Gaskets sold separately (Cummins 3977913 gasket set)
• Interstate-McBee aftermarket line

Specifications:

• Base part number: M-3959031 (3959031)
• Component type: Engine oil cooler (7-plate, stacked-plate)
• Condition: New Aftermarket (Interstate-McBee)
• Engine: Cummins ISB / QSB 5.9L (24-valve common rail)
• Years: 2003-2007

Compatibility / Fitment:

• 2003-2007 Dodge Ram 2500/3500 with the 5.9L Cummins (ISB, 24-valve common rail)
• Industrial and off-highway ISB / QSB 5.9L applications where 3959031 is specified — verify by ESN
• Gaskets not included — order the gasket set (Cummins 3977913) separately

Conclusion:

A new aftermarket 7-plate oil cooler (Cummins 3959031) for the 2003-2007 5.9L ISB/QSB, restoring proper oil temperature control. Gaskets are not included; verify your engine by ESN and add the gasket set before ordering.